From the Start, I Had a Shinigami System and Became Light Yagami

I woke up as Light Yagami, and even got a Shinigami System that lets me kill whoever I want? I find a notebook in a bar from the start, then immediately make Misa Amane mine! I was hoping for a carefree, satisfying life, but then Zhang Feng shows up with a Savior System and insists on helping L take me down? Fine! Let’s see whose cheat is stronger! I develop a formula for killing people, type in a name on my computer, and they’re dead anywhere in the world in seconds. Tell me, aren’t you scared? L screams in frustration: “His crimes have no psychological motive!” Zhang Feng breaks down: “His System level is higher than mine!” When the whole world begs me to stop, I just smile. I can’t stop now. My formula is calculating how to... kill a god!